1. Field of the Invention
This invention relates to a method for reducing printer response time in a word processing system having a variable keyboard data rate. In particular, the invention pertains to a buffering scheme suitable for a variety of printers associated with a word processing system to improve the response time of the printers from keyboard commands controlling the printer.
2. Description of Prior Art
Word processing systems have been developed to enable an operator to create an output or printed copy of a document. As the operator types the document, the characters and commands entered from the keyboard are visually displayed and are written onto a diskette. Upon completion of the keying of the document, the systems enable the operator to select a print task for reading the document off the diskette a line at a time and having each line translated into printer commands for outputting a hard copy of the document.
Improved word processing systems have been developed with expanded capabilities to enable the operator to produce a hard copy on a printer one character at a time in direct response to keyboard entries. The IBM Displaywriter word processing system's Key to Print feature provides the operator with such a capability. The Key to Print feature enables the operator to use the word processing keyboard controlled printer for typewriter-like typing tasks, such as filling in printed forms, without going through the intermediate step of displaying the completed typing task on the display and writing it onto the diskette. In the direct keyboard to printer typing environment, data from the keyboard is variable and irregular, and the several types of printers associated with word processing systems are designed for optimum operation as line printers. One printer works best, one logical command at a time, but other printers may work best in receiving multiple logical commands at one time, e.g., eight or ten commands. The varying input data rate in the keyboard to printer typing environment means that there is less than an optimum response time from the printer. A need has thus arisen for a method to minimize the observed delay time from operator key-stroke to printer completion to keep the printer operating at optimum speed when receiving variable sized input records.